Amazon has scored another hit in the battle of the online music stores by adding Warner Music Group to its library of good quality (256kbps) unprotected MP3 music files. Unlike files from Apple's iTunes, the Amazon library has no proprietary DRM (digital rights management) lock-in, and the files will play "on virtually any personal digital music capable device -- including PCs, Macs(TM), iPods(TM), iPhones(TM), Zunes(TM), Zens(TM)," says Amazon's press release.

The unprotected MP3s will also play on open systems Linux and other platforms for which Apple excludes support.

In addition, Amazon and WMG will make available to consumers digital music products such as album bundles containing exclusive tracks.

Some of the Amazon files should also be cheaper. "More than 1 million of the over 2.9 million songs [are] priced at 89 cents", says Amazon, and "the top 100 best-selling albums are $8.99 or less, unless marked otherwise."

Amazon doesn't say which WMG artists it's carrying, but the Reuters report notes that WMG acts include Linkin Park and the Red Hot Chili Peppers. It also owns Rykodisc, and therefore the Frank Zappa catalogue.

Warner Music used to be part of Time Warner but is now a public company run by the somewhat controversial Edgar Bronfman, Jr, a noted campaigner against peer-to-peer file sharing. In February 2007, in a conference call with financial analysts (transcript), Bronfman said:

Let me be clear: we advocate the continued use of DRM in the protection of our and of our artists' intellectual property. The notion that music does not deserve the same protections as software, television, film, video games or other intellectual property simply because there is an unprotected legacy product available in the physical world is completely without logic or merit.

We will not abandon DRM, nor will we disadvantage services that are successfully implementing DRM for both content and consumers.

Sony BMG has still to convert to DRM-free music, or to MP3. The Sony Connect music store is still touting its own "high-quality music format, ATRAC® -- superior in audio quality to the average MP3."